Floor scrubbing device



8 4, 1942- v. H. MENKHAUS 2,291,740

FLOOR SCRUBBING DEVICE Filed Dec. 12, 1938 2 Sheets-Sheet l mm; -5.m||||INVENT OR.

BY m 2/ W a ATTORNEYfi 4, 1942- v. H. MENKHAUS FLOOR SCRUBBING.DEVICEFiled Dec. 12, 1938 2 Sheets-Sheet 2 Patented Aug. 4, 1942 UNITED STATESPATENT OFFICE FLOOR SCRUBBING DEVICE Victor B. Menkhans, Cincinnati,Ohio Application December 12, 1938, Serial No. 245,063

2 Claims.

This invention relates to cleaning apparatus and is particularlydirected to an improved floor scrubbing machine. The invention alsodeals with the use of the machine with other driven parts such assanders, waxers, polishers, etc.

Heretofore, power driven machines of this character have been undulyheavy, hard to handle, and extremely difficult to clean. Moreover,considerable difliculty has been experienced in properly delivering thewater to the brush, as in a scrubbing machine, as well as in removingthe brush for cleaning or for interchangement with other parts. Becauseof the very nature of the use to which the equipment is put, it followsthat considerable dirt accumulates on the apparatus and this must beperiodically removed. The floor scrubbing apparatus of the past hasincluded water tanks and control valves. Also, no thought has been givento arranging the machine so that it was properly balanced for eitherdirection of drive and in this respect facilitating handling anddirecting of the machine in the operation.

It has been the object of the present inventor to provide an improvedpower driven apparatus for scrubbing, polishing, sanding, or for anyother allied use which accomplishes one or more of the followingresults: facilitates cleaning of the apparatus, due to a structuralarrangement eliminating unnecessary obstructions; provides means forsupplying water to a scrubbing unit without the necessity for a tankmounted direct- 1y on the apparatus; mounts the brush, sander, orpolisher in a simple manner for universal movement; provides fordelivery of the water through the scrubbing brush and rotativeconnection of the brush to the driving means through a novel couplingarrangement; greatly simplifies the structure by incorporating the motorand gear case unit rigidly in one casing; disposes the motor and gearcase unit at the correct angle to balance the weight when the drivenelement is running clockwise or counterclockwise; provides means forvarying the angle of the handle to suit the height of the operator;disposes the handle gripping means at the correct angle for convenientoperation; and provides an exceedingly simple arrangement for extendingthe electrical cords to the motor through the handle, eliminating, inthis respect, unnecessary drilling.

Other objects and certain advantages will be more fully apparent from adescription of the accompanying drawings in which:

Figure 1 is a perspective view of the improved machine.

Figure 2 is a top plan view of the machine with a portion of the handlebroken away.

Figure 3 is a sectional view taken on line 3--3, Figure 2, detailing thegeneral construction of the machine.

Figure 4 is a fragmentary sectional view enlarged out of Figure 3,showing the details of the connection of the driven element and thedrive means.

Generally described, the machine provides a base, a motor and gearcasing unit mounted on the'base, a coupling, a rotary scrubbing brush inthe present instance, wheels at the rear of the base, and a handle forpropelling the machine.

Referring to'the drawings, the base is generally indicated at l0 andconsists of a substantially flat plate having a virtually unobstructedunderside except for reinforcing ribs H along its side edges. The baseprovides a horizontal portion upon which the motor I2 is mounted andattached by means of bolts I3. The rear portion of the base slopesslightly as indicated at M and includes a pair of lugs l5, one at eachside thereof, extending upwardly from the surface of the plate. An axleI6 is disposed through these lugs and carries rubber composition wheelsII on its extended ends.

The handle I8 is formed of tubing in the form of a T, the head IQ ofwhich is traversed by the axle and disposed between the lugs. The

upper end of the handle is provided with a crossbar 20 having rubbergrip elements 2| at each end thereof. A switch box 22, incorporating aswitch 23, is provided at the juncture of the handle and the crossbar.An extension cord 24 extends from this box and carries a plug 25 on itsend for attachment to any floor socket which may be available. Thisextension cord, when notsin use as shown in the drawings, is reeledabout a pair of spaced prongs 26 along the handle. The electrical leadsextend from the switch box down through the tubing and project from thetubing at the juncture of the head or axle engaged endthereof fromwhence they extend to the terminal box 28 of the motor.

In order to avoid boring of the shank of the handle, the handle elementis of larger tubing than the head portion through which the axleis-engaged and is welded to .the head with its axis offset from the axisof the head. Thus,

when the welding is complete, a portion of the end of the pipe is leftopen as indicated at 29 and the electrical leads extend out of thisopening.

The handle is held in fixed relation with respect to the base and motorby means of a chain ll, having one end coupled to a clip ti on thehandle and the other end hooked over 9. prong 82 cast on the motor head.

The transmission or gearing unit, which consists preferably of a wormand worm wheel (not shownhis formed as a part of the head 34 of themotor and projects laterally therefrom, disposing the axis of the wormwheel in a vertical plane. The motor is set on the base at an angle sothat the axis of the drive shaft Ii or the worm wheel is disposed on thecentral line of the base and handle (see Figure 2). Thus it makes nodifference which way the rotary scrubbing brush is running insofar asthe balance of the machine is concerned.

If the motor were straight and the axis of drive were offset from thecenter of the machine, the distribution of weight would be uneven andthe machine would tend to hang over on one side. If the drive of thescrubbing element happened to be in a direction tending to shift theweight in this same direction, it would make the machine diflicult tohandle and the tendency would. be for the scrubbing to take place on oneside of the brush only. The normal tendency to shift, due to thescrubbing action, is not sumcient to cause this irregularity ofscrubbing if the weight is evenly distributed and this is the resultachieved by the arrangement shown. Thus, it makes no difference whetherthe brush is running clockwise or counterclockwise. The

machine is always in substantial balance.

Other means, hereinafter described, aid in providing a uniform scrubbingaction. Now, as shown in detail in Figure 4, the coupling or drivingelement 36 has its hub socketed upon the lower end of the drive shaft35. A key 3! prevents relative rotation of the shaft and element and aset screw 38 holds the element against longitudinal displacement.

This element provides three downwardly projected teats 39. These teatsare evenly circumferentially spaced and are fed from a receptacle formedon the top of the element by an angular flange 40. The water isdelivered to the receptacle, indicated at 4|, through a conventionalhose engaged in a slotted element 42. The end of the hose is disposed inthe receptacle. This hose is not shown but will be readily understood asof conventional form.

These teats not only function as the means for feeding the water to thebrush, but have the added function of providing a coupling connectionbetweenthe driving element and the brush. They enter vertical aperturesIt in the base or body portion 44 of the brush 4!. The brush 4! providesthe conventional bristles 46 projecting fromits entire underside, withthe exception of the central portion into which the water is delivered.The brush is held upon the driving element by means of a wing nut 41,screwed upon a threaded stud projecting downwardly from the central axisof the driving element. The wing nut is contained within the countersunkportion' of the base of the brush. The wing nut is never tightened tothe point where it binds the brush in position, but a certain amount ofplay is permitted-so that the brush may rock relative to the stud. Thisoccurs without interference from the driving element. The rocking actionis assisted by the engagement of the brush with a convex portion 49 ofthe coupling.

Having described my invention, I desire to be limited only by thefollowing claims:

1. A floor scrubbing machine providing, a base, wheels at the rear ofthe base, a motor driven unit mounted on the base and having a verticalshaft, a dished coupling element fixed to the shaft providing downwardlyextended rigid teats circumferentially arranged around the coupling, arotary scrubbing brush providing apertures into which said teats enterloosely, the relationship of said teats and apertures providing therotary driving connection between the coupling and the scrubbing brush,and means axially loosely attaching the coupling and the brush, forholding the brush loosely in position, said coupling providing a convexunderside against which the brush engages, whereby the brush is free torock on the coupling.

2. A power driven floor scrubbing machine comprising a base ofsubstantially flat plate construction having a substantiallyunobstructed underside, said plate providing a normally horizontallydisposed forward portion and a slightly inclined rear portion, a shaftjournalled on said base above the upper surface of the rear portionthereof, wheels on said shaft for supporting the rear of said base, amotor mounted on the horizontally disposed forward portion of said baseand including a transmission unit extended forwardly therefrom as aunitary part of the motor, said transmission unit overhanging theforward end of the base and including a vertically downwardly disposeddriving shaft, a rotary scrubbing brush mounted on the lower end of saidvertically downwardly disposed driving shaft having its axis disposed onthe longitudinal center line of the base, and means for propelling saidmachine.

VICTOR H. MENKHAUS.

